Art of producing wax modifying agents



Patented Au 5, 1941 ART or PRODUCING AGENTS WAX MODIFYING Eugene Lieber, Linden, N. J., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application December 7, 1937. Serial No. 178,530

6 Claims.

The present invention relates to the art of producing wax modifying agents which may be employed for reducing the pour point of waxy lubricating oils, or in connection with processes for dewaxing oils containing paraffin wax, or in any other process or composition in which a wax structure is to be modifiedby reducing the crystal size.

, perior wax modifying agents may be. produced from fatty acid halides without the use of aromatic compounds. The exact structure of these materials is not fully understood, but it is believed that they are poly-ketones. They are clearly distinguished from the ketonic materials mentioned above because they do not contain aromatic groups. The nature of the materials in detail below.

In producing the present products, acid halides The invention will befully under-- stood from the following description.

and the inethod of manufacture will be described containing hydrocarbon chains of. at least ten carbon atoms are used as the raw material. Naturally occurring fatty acids such as stearic, oleic, palmitic and the like may be employed, either alone or in mixtures, but such materials are relatively expensive and it has been found that acids produced by the oxidation of paraflin wax are cheaper and even more effective. These -materials consist of mixtures of waxy acids having from 10 to 20 carbon atoms in the chain, and

such a mixture can be used advantageously. If desired, however, narrower cut fractions may be employed, for example, having from l0 to 14 carbon atoms or 13 to 16 carbon atoms. Thus if it is desired to-utilize a certain fraction of the acids for some other purpose, the remaining acids may be used for present purposes.

The first step in the process is to convert the fatty acid, or mixture of fatty acids, into acid halides and this may be accomplished by any known process. For example, the acid may be reacted with phosphorus trichloride. The reaction occurs smoothly at about the temperature of boiling water and the acid chloride forms an oilylayer on' top of the aqueous phosphorus acid and may be decanted therefrom.

The acid halide, preferably acid chloride, is then polymerized by gently heating to a temperature from say 400 to'750 F., care bein taken to hold the temperature below that at which carbonization occurs. The heating is carried out for seyeral hours until the evolution of hydrogen chloride has practically ceased. The nature of the reaction is not fully understood, but it is obvious that the hydrogen halide is split from the acid halide, and it is believed that the formation of a high 'molecularweight ketone occurswhich probably immediately begins to polymerize. Thicke'ningis noted during the heating period and heating may be con- .tinued after all of the hydrogen chloride has been evolved in order to effect further polymerization. Catalysts are not necessary for the process, butit is desirable to conduct the reaction under a condenser so that if the relatively heavy materials tend to vaporize, they will be returned for further reaction.

After polymerization, the product is preferably diluted with a suitable solvent, such as alcohol, kerosene or the like, and it is washed free from acid. The solvent is then removed by distillation and the wax modifying agent is collected as a distillationresidue: The distillation is preferably carried out under-vacuum to a temperature of say 500 F., in order to remove low boiling materials. The final product is a viscous, gummy material of good color and freely soluble in 'm ineral' oils.

This product may be used as such or may be further purified by hydrogenation, acid treatment or the like. When used as a pour depressant, it is employed in quantities from say 0.1 to 5%, although usually 1% is suflicient for most purposes. It will be understood that different oils require slightlydifferent amounts of the material for a given pour depression, andlikewise materials made up from different types of acids vary somewhat in their pour depressingstrength. 7 1

These modifying agents may be used in .con-

'nection with processes for dewaxing hydrocarbon oils and then added either to the oil to be dewaxed, or to the oil after it has been diluted with naphtha, or with other suitable dewaxing or centrifugati'on. In any case, it will be found that the presence of a relatively small amount I claim: 7 1. An improved composition of matter comprising a waxy lubricating oi1 and a small amount of a pour depressing compound, prepared by subducing pour point depressants, the following ex- I periments may be considered:

Example I 100 grams of fatty acids, produced by the oxidation of paraffin wax with air at a temperature from 100 to 125 C., were mixed with 30 grams of phosphorus trichloride. The mixture was allowed to stand on a water bath until a layer of the fatty acid chloride was formed on top of the aqueous layer. This material was then drawn off and heated in a flask for two hours at a temperature of 575 F., under an air condenser. During the heating, dense fumes of hydrogen chloride were evolved and the material in the flask at 5 mm. mercury pressure, to a temperature of 500 F. A portion of the lower boiling material was removed and the distillation residue amounting to 65 grams was recovered. This product was a viscous, gummy oil, freely soluble in mineral lubricating oil.

-In order to test the pour depressing power of this material, 1% thereof was added to a waxy oil which originally had a pour point of 30 'F. It was found that the pour point .of the blended product was depressed to slightly below 30 F.

Example II l'grams ,of stearic acid was converted to stearyl chloride by treatment with 30 grams of phosphorus trichloride in the same manner described for the wax-acids in Example No. I. The stearyl chloride was drawn off and heated in a flask to 575 F. It was found in this case that a .much longer period of heating was required before the evolution of hydrogen chloride had practicallyceased, namely hours. The heating was then discontinued and the product recovered as described in Example No. I, 55 grams of vacuum distillation residue being obtained. 1% of this material added to the same waxy oil, of Example No. I, depressed the pour point to F.

' The polymerization products per se and -the method of preparing same are claimed in copending-application, Serial No. 371,993, filed De-. cember 27, 1940.

The present invention is not to be limited by any theory of the mechanism ofthe process nor to the use of any particular fatty acid or mixture thereof, but only to the following claims in which it is desired to claim all novelty inherent in the invention.

jecting a mono, basic fatty acid chloride having a chain of at least 10 carbon atoms to the action of heat at a temperature of about 575 F., whereby hydrogen halide is evolved and the organic residue is polymerized, and continuing the heating at said temperature until substantially all of the halide has been removed.

2. An improved composition of matter comprising a waxy lubricating oil and a small amount of a pour depressing compound prepared by subjecting an aliphatic monobasic saturated fatty acid chloride having at least 10 carbon atoms in the molecule to the action of heat at a temperature between 400 and 750 F. whereby hydrogen chloride is evolved and the organic residue is polymerized and continuing the heating at said temperature until substantially all of the halide has been removed.

3. An improved composition of matter comprising a waxy lubricating oil and a smal1 amount of a pour depressing compound prepared by subjecting a monobasic fatty acid halide having a chain of at least 10 carbon atoms in the absence of a condensing catalyst to the action of heat at a temperature between 400 and 750 F. whereby hydrogen halideis evolved and the organic residue is polymerized and continuing the heat- .ing at said temperature until substantially all of the halide has been removed.

4. An improved composition of matter comprising a waxy lubricating oi1 and a small amount of a pour depressing compound prepared by subjecting a material consisting of a monobasic fatty acid chloride having at least 10 carbon atoms in the molecule to the action of heat at a temperature between 400 and 750 F. whereby hydrogen halide is evolved and the organic residue is polymerized and continuing the heating at said temperature until substantially all of the 575 F. for about two hours under an air convacuum at about 5 mm. mercury pressure to a temperature of about 500 F., whereby a residue consisting of a viscous gummy oil freely soluble in mineral lubricating oil is obtained.

' 6. Composition according to. claim 2 in which the pour-depressing compound 'is prepared by heating stearyl chloride.

EUGENE LIEBER. 

